WO2014122176A1

WO2014122176A1 - Force feedback mini-shaft for electromagnetic control

Info

Publication number: WO2014122176A1
Application number: PCT/EP2014/052255
Authority: WO
Inventors: Benoît Lopez
Original assignee: Midi Ingenierie
Priority date: 2013-02-05
Filing date: 2014-02-05
Publication date: 2014-08-14
Also published as: FR3001706B1; EP2954382A1; US20160018843A1; FR3001706A1

Abstract

The invention relates to a mini-shaft that comprises: a joystick (2); a hinge part (4) having a first portion (8) having a first magnetic polarity, and a second portion (10) having a second magnetic polarity; a connection between the hinge part (4) and the joystick (2); a first part (12) arranged opposite the first portion (8); a second part (14) arranged opposite the second portion (10); first polarization means (18) enabling the parts (12, 14) to be controlled; sensors of the position of the joystick (2); and control means which perform control on the basis of the measurement signals from the sensors and of a predetermined force feedback rule.

Description

MINI-HANDLE OF ELECTROMAGNETIC CONTROL TO RETURN

EFFORT

The present invention relates to a mini-joystick electromechanical control force feedback.

One field of application of the present invention is the production of mini-handles for the piloting of aircraft, such as for example an airplane or a helicopter. In the aeronautical field, an aircraft is a flying apparatus having levitation means and propulsion means enabling it to move. To control an aircraft, control means are provided and they act on moving elements called control surfaces. When the aircraft flies, it can pivot about three axes, called pitch axis, roll axis and yaw axis by acting on the corresponding control surfaces provided for this purpose.

A handle means a device allowing an aircraft pilot to control the attitude of the aircraft on its pitch and roll axes. These actions then make it possible to incline the device in turn and change of altitude.

Conventionally, a cable system provides a connection between the handle and the control surfaces and a pilot, by operating the stick, directly transmits his efforts to the control surfaces. This device is still used on "light" aircraft. On heavier planes, hydraulic devices can assist the pilot. Finally, on recent aircraft, it is common that the control surfaces are connected to electric actuators and that the handle thus transmits more physical effort. In this case, the handle is most often reduced in size and is then called mini-sleeve. Subsequently, the term sleeve designates both a "classic" handle that extends from the ground (of a cockpit) to the hand of a pilot sitting on a pilot's seat that a mini-handle is presenting in the form of a controller and can take place at various locations in an aircraft cockpit within reach of course a pilot. In addition, the term pilot refers to both the pilot of an aircraft (airplane, helicopter or other) than a possible co-pilot.

In a modern aircraft, the link between the control stick and the control surfaces the aircraft is thus provided by a transmission system associated with electronic control means and providing the necessary forces, for example by driving electric actuators, to impose the control surfaces to take the orientation corresponding to the position of the handle. As there is no direct interaction between the handle and the control surfaces, the latter can not return a feedback effort on the handle.

For a variable resistance opposes the movement of the handle actuated by the pilot, it is known to provide the handle with a force feedback device simulating a control-feedback effort of the control surfaces on a "conventional" handle. Most often, a mini-stick has a joystick guided by a system with gimbals and rods which are associated with various sensors including position sensors. The return of effort is often obtained by simple springs. This solution does not make it possible to control the counter-reaction force. It is also known to use reducers or linear type cylinders. However, reversibility problems arise.

Document DE-195 01 439 discloses an electromechanical device having a moving part, or rotor, on which an electromagnetically produced torque can be exerted. This torque is transmitted without contact and without mechanical coupling to the rotor. The stator comprises a cylinder head with a base and side pieces as well as pole pieces having a slot defining two teeth. The rotor is formed of a magnetized cylinder or ring disposed between an upper pole piece and a lower pole piece and an actuating handle. The rotor is mounted on a bearing leaving him two or three degrees of freedom. A current flowing in coils associated with the side pieces produces a magnetic field which is asymmetrical when the handle is not at rest and thereby creates a return torque by the reluctance effect.

The document WO-00/03319 discloses a control system for a pointer placed on a computer screen or the like, using a pointing device of a type known per se. The pointing device includes an indicator device providing tactile feedback to the user for transmitting information on the movements of the pointers on the screen. This indicator device is designed to transmit information in at least two dimensions. The system used here uses an operating principle very similar to that described in document DE-195 01 439, without however presenting an operating handle.

These devices of the prior art allow the creation of a torque by varying the reluctance in an electromechanical system. The created torque is a return torque in a reference position. It is not intended here to act on the system to bring it to a position other than this reference position.

The present invention therefore aims to provide a mini-handle having a force feedback system for exerting on the lever of a mini-stick a representative effort of a return force of control surfaces. Thus, the return of forces is not necessarily controlled by a law dependent solely on the position of the mini-handle but may involve other parameters. Advantageously, the system provided by the invention will position the mini-stick in various positions without mechanical action on it.

The proposed device will be advantageously compact and preferably more compact than current systems so as to obtain a mini-sleeve less bulky than the known mini-sleeves.

The present invention firstly proposes a mini-joystick with a force feedback control comprising a lever having a degree of freedom in rotation around a first axis of articulation.

According to the present invention, such a mini-handle comprises:

a part called the first articulation part having a first part with a first magnetic polarity and a second part with a second magnetic polarity opposite to the first magnetic polarity,

- Reversible movement transmission means between the first articulation part and the handle connecting the first articulation part to said handle so that a rotational movement of the handle around the first axis of articulation is transmitted to the first articulation piece which can also cause the handle to rotate about its first axis of articulation, at least one pole piece, called the first pole piece, arranged facing substantially (or only) the first part of the first articulation part,

at least one other pole piece, called the second pole piece, arranged facing substantially (or only) the second part of the first articulation piece,

first polarization means making it possible to act on the first pole piece to polarize it according to the first magnetic polarity,

second polarization means for acting on the second pole piece to polarize it according to the second magnetic polarity,

means providing measurement signals representative of the position and / or movement of the handle or the first articulation piece, and

control means acting on the first biasing means and on the second biasing means so as to vary the magnetic field created by the first polarization means and the magnetic field created by the second polarization means as a function of the polarization signals; measuring position and / or movement and possibly a predetermined force return law.

This original structure for a mini-stick proposes to put the joystick on magnetic bearings and to act on magnetic fields reigning at air gaps to control a return torque (or return efforts) on the joystick. It is also possible with such a structure to act on the joystick to move it only by managing the polarization means.

It should be understood by means of transmission both a direct connection (by screwing, gluing, etc.) in which the handle and the articulation piece are integral with one another that a connection involving intermediate parts movable relative to the handle and / or the articulation piece.

The term "essentially" is used to signify that each pole piece is placed opposite a single part of the articulation piece and that it is not expected that it will come into contact with to the other part of the articulation piece. It may possibly come to overflow the part of the articulation piece in front of which it is in function in particular of the position of this articulation piece but such an overflow remains marginal. The aim here is to put a pole piece with a magnetic polarity opposite one side by the polarization means and on the other side a part of the hinge piece with a single polarity (and not not vis-à-vis two different polarities as in the state of the art).

Advantageously, it can be provided that each pole piece is only facing a portion of the hinge piece in a position that could be called neutral position, or rest position. It can also be provided that the pole pieces are such that in all positions of the hinge piece, each pole piece is facing a single part of the hinge piece.

Most often, the control of the joystick is intended to achieve a force feedback and a predetermined force return law is used to control the device. However, in the case of automatic control of the position of the joystick, without action of an operator, a control law other than the evoked force feedback law will be used to control the joystick.

The structure proposed above concerns a mini-stick with a joystick with a degree of freedom. This structure can also be adapted to a mini-handle whose handle has a second degree of freedom around a second axis of articulation. Such a mini-handle then includes, for example, in addition:

a part called a second articulation part having a third part with a first magnetic polarity and a fourth part with a second magnetic polarity opposite to the first magnetic polarity,

reversible movement transmission means between the second articulation piece and the handle connecting the second articulation piece to said handle such that a rotational movement of the handle around the second articulation axis is transmitted to the second hinge piece that can also cause the controller to rotate around its second axis of articulation,

at least one pole piece, called the third pole piece, arranged facing essentially (or only) the third part of the second articulation piece,

at least one other pole piece, called the fourth pole piece, arranged facing essentially (or only) the fourth part of the second articulation piece,

third polarization means making it possible to act on the third pole piece to polarize it according to the first magnetic polarity, and

fourth means of polarization making it possible to act on the fourth pole piece to polarize it according to the second magnetic polarity.

This structure is a combination of two structures adapted for a joystick with a degree of freedom.

The present invention proposes on the same inventive principle as above, a mini-joystick with a force feedback control comprising a joystick having a first degree of freedom in rotation about a first axis of articulation and a second degree of freedom in rotation about a second axis of articulation.

This mini-sleeve comprises:

a part called hinge part having a first part having a first magnetic polarity and a second part having a second magnetic polarity inverse of the first magnetic polarity,

reversible movement transmission means between the articulation piece and the handle connecting said articulation piece to said handle so that the movements of rotation of the handle around the first articulation axis and around the second axis articulation are transmitted to the articulation piece which can also cause the handle to rotate about the first articulation axis and around the second articulation axis,

at least two pole pieces, called the first pole piece and the third pole piece, arranged facing substantially (or only) the first part of the articulation piece,

- at least two other polar pieces, called second pole piece and fourth pole piece, disposed vis-a-vis essentially (or only) of the second part of the articulation part,

first polarization means for acting on the first and third pole pieces to polarize them according to the first magnetic polarity,

second polarization means for acting on the second and fourth pole pieces to polarize them according to the second magnetic polarity,

means providing measurement signals representative of the position and / or movement of the handle or articulation piece, and

Here, according to the same principle, for a mini-handle with a joystick with two degrees of freedom, the same piece of articulation is used for the two axes of articulation.

In a mini-handle according to the present invention, that it has one or more articulation parts, it is proposed that at least one articulation piece, but preferably each articulation piece, comprises a central magnet placed between two parts made of a magnetic material so that a part is polarized by the magnet according to a first magnetic polarity and that the other part is polarized by the magnet in a magnetic polarity inverse to the first magnetic polarity.

The polarization means implemented in a mini-stick according to the invention comprise for example a coil disposed around a core of magnetic material and means for supplying the coil with electrical current.

To guarantee the polarization of each pole piece, even in the absence or failure of polarization means, each pole piece is advantageously polarized by a magnet. It is thus possible to obtain a stable position of the mini-handle even in the absence of current.

In a mini-stick according to the present invention, in order to create air gap changes when the articulation piece is moved, it is advantageously provided that each pole piece disposed vis-à-vis a portion of articulation part has a surface facing the hinge piece made so that during a rotation of the hinge piece about an axis of articulation the distance between a given point of said surface and the hinge piece varied.

Details and advantages of the present invention will become more apparent from the description which follows, given with reference to the appended schematic drawing in which:

FIG. 1 schematically shows in elevation a first embodiment of the present invention in which a mini-handle has a handle with a single degree of freedom,

FIG. 2 is a view similar to that of FIG. 1 in which the handle is in a different position,

FIG. 3 is an enlarged detail view of FIG. 2 illustrating the forces and torques involved,

FIG. 4 is a schematic perspective view of a second embodiment of the present invention in which a mini-handle has a handle with two degrees of freedom,

FIG. 5 illustrates an alternative embodiment for the embodiments of the preceding figures,

FIG. 6 schematically illustrates in perspective a third embodiment of the present invention,

FIG. 7 schematically illustrates in perspective a fourth embodiment of the present invention,

FIG. 8a is a diagrammatic elevational view of a fifth embodiment of the invention,

Figure 8b schematically illustrates in perspective the fifth embodiment of Figure 8a, and

Figure 9 schematically illustrates an example of architecture overall of a mini-handle according to the present invention.

The present invention relates to a mini-stick that can be used for piloting an airplane or a helicopter. However, other applications of the present invention can be envisaged, for example for a control system in a land or naval machine, for example construction equipment, crane, ship, submarine, ....

In a conventional manner, a mini-handle has a housing (not shown in the drawing) inside which there is a mechanism associated with a lever 2. In an original manner, the mechanism has magnetic bearings and / or a magnetic ball as described below.

In an aeronautical use, most often the lever 2 is rotatable about two axes of articulation. To better understand the principle implemented by the present invention, Figures 1 to 3 relate to movement only around a single axis of articulation. It is conceivable to have a mini-handle whose lever 2 moves with only one degree of freedom without departing from the scope of the present invention, even if the present invention is more particularly adapted to a mini-handle with a joystick with two degrees of freedom.

In the first embodiment (Figure 1 to 3), the handle 2 is associated with a hinge piece which is here in the form of a ball 4 on which it is fixed. The ball 4 is mounted on magnetic bearings defined by polar parts described below.

The ball 4 of Figures 1 to 3 is formed of a magnet 6 having a north pole and a south pole, a first half-sphere 8 and a second half-sphere 10.

The magnet 6 has the shape of a disk and is cut in a magnetic material so that the north pole corresponds to one face of the disk and the south pole to the opposite face. Each half-sphere here has a diameter corresponding to the diameter of the magnet 6. A planar face of each half-sphere coincides with one face of the magnet 6. We thus find the magnet 6 sandwiched between the first half -sphere 8 and the second half-sphere 10. These two half-spheres are each made of a magnetic material so that they are both polarized. We assume for example that the first half-sphere 8 corresponds to the north pole of the magnet 6 while the second half-sphere 10, of magnetic polarity opposite to the magnetic polarity of the first half-sphere 8, corresponds to the south pole of the magnet 6.

It is proposed here to arrange the first half-sphere 8 facing two first pole pieces 12 polarized so as to correspond to a north pole and to have the second half-sphere 10 facing two second pole pieces 14 polarized so as to correspond to a south pole. In this way, the pole pieces exert a repulsive force on the ball 4 and form magnetic bearings. We note here that each pole piece only faces a part of the ball 4, that is to say a half-sphere, without coming to face the other part (half-sphere) of the ball which is polarized in reverse.

Two sets are thus made around the ball 4, each set comprising a first pole piece 12, a second pole piece 14 and a magnet 16. As illustrated in FIGS. 1 and 2, each set has a global shape of a C clip. In each set, the magnet 16 is placed between the first pole piece 12 and the second pole piece 14 so that the first pole piece 12 is on the north pole side of the magnet 16 and the second pole piece 14 on the side of the south pole of the magnet 16. FIG. 4 in perspective illustrates four sets such as the two sets shown in elevation in FIGS. 1 and 2 and shows an example of shapes that can be adopted by the pole pieces and arrange them around of a ball 4.

In the embodiment of FIGS. 1 to 3, four air gaps are made between, on the one hand, the ball 4 and more specifically a part of given polarity of the ball 4, that is to say in the embodiment illustrated the half-sphere 8 or the half-sphere 10, and, secondly, each of the pole pieces. In these gaps reigns each time a magnetic field which is such that it tends to move the ball joint from the corresponding pole piece. To be able to vary the magnetic fields prevailing in the gaps, and thus act on the ball 4 (without external action, an equilibrium position would be established), it is expected to associate with each pole piece an induction coil 18 who comes to surround partially the corresponding polar piece. It is noted in Figures 1 and 2 that in the same assembly (formed of a first pole piece 12, a magnet 16 and a second pole piece 14) induction coils 18 arranged around the first pole piece 12 and around the second pole piece 14 are connected so that the same current flows in the two coils 18 of the same set. Depending on the flow direction of the current in the coils 18 of a set, a magnetic field will be added to, or subtracted from, the magnetic field corresponding to the bias field of the corresponding magnet 16.

Figure 1 illustrates the ball 4 in an equilibrium position, the lever 2 is then in a position called neutral position. In this position, it is assumed that all the air gaps (between each of the two parts of the ball 4, that is to say here the half-sphere 8 and the half-sphere 10, and each of the pole pieces) is the same. . It is further assumed that the shape of the surfaces of the pole pieces facing the ball 4 is adapted to the outer spherical shape of each of the half-spheres so that the air gap between the half-sphere and the pole piece is of substantially constant thickness.

Figure 2 illustrates the handle 2 in a position rotated relative to the equilibrium position of Figure 1. This position can be reached either following an action of a user on the lever 2, or following a modification of the magnetic fields around the ball 4. It is noted here that the air gaps defined in the previous paragraph have changed. Indeed, each pole piece faces the ball 4 a spherical shape but the four spherical surfaces belong to two separate spheres. In addition, the axis of rotation of the ball does not correspond to a main axis (or revolution) of these two spheres. There is therefore modification in the air gaps between the half-spheres of the ball 4 and the pole pieces.

FIG. 3 illustrates forces exerted on the ball 4 and issuing from the magnetic fields surrounding it when the ball 4 is in the position shown in FIG. 2. In FIG. 3, a mark with FIG. an abscissa axis (marked x) and an ordinate axis (marked y). The x-axis can be assumed to be horizontal while the y-axis is assumed to be vertical. This orientation is chosen here for the description but another orientation could also be chosen.

FIG. 3 also shows a force F1 1 which corresponds to the force exerted by a first set on the first half-sphere 8. Likewise, forces FI 2, F 21 and F 22 respectively correspond to the action exerted by the first set on the second half-sphere 10, the action exerted by the second set on the first half-sphere 8 and the action exerted by the second set on the second half-sphere 10. In the chosen embodiment and represented in FIG. 3, these forces are supposed to be exerted in the center of the junction surface between the half-sphere concerned and the magnet 6.

The resulting force F01 (= F1 1 + F21) acting on the first half-sphere 8 has components Fx1 and Fy1 respectively on the abscissa axis and on the ordinate axis. Similarly, F02 (= FI 2 + F22) acting on the second half-sphere 10 has components Fx2 and Fy2 respectively on the abscissa axis and on the ordinate axis.

The thickness of the magnet 6 is called in FIG. 6. This thickness also corresponds here to the distance separating the points of application of the forces F01 and F02. The forces along the x-axis then produce a counter-effort pair C = ( ^{Fx1 + Fx2} )

2ε

Note that in the equilibrium position illustrated in Figure 1, the ball 4 is in a position such that the application points of the forces F01 and F02 are on the ordinate axis. The resulting forces are further aligned on the y-axis. Because of this, there is no resulting torque. On the other hand, the tilting of the ball joint or the modification of the magnetic fields in the pole pieces by applying currents in the induction coils modifies the ratio of the amplitudes of the applied forces, thus causing a reaction torque.

In this proposed embodiment, it is noted that when the handle 2 is in the rest position, its axis is an axis of symmetry for the system described above. Whatever the inclination of the ball 4 and the amplitude of the magnetic fields (of polarization and induced by the coils), there is always a position for which the forces, at the points of application defined previously, are parallel and so amplitude given the possible variations of gaps. In this position the ball 4 is then in stable equilibrium from the point of view of the translations along the x or y axes independently of the currents in the coils and independently of the induced reaction torque if the forces are not collinear.

FIG. 4 illustrates an embodiment of the invention in which the handle 2 is rotatable along two axes of articulation. In this embodiment, we find the elements illustrated in FIGS. 1 and 2 and add a third set and a fourth set similar to the first set and the second set. The third set is arranged with respect to the fourth set in the same manner as the first set is relative to the second set. The third set and the fourth set are then arranged around the ball 4 being offset with respect to the first set and the second set of 90 °.

In this way, as explained with reference to FIGS. 1 to 3, a system is provided making it possible to generate force feedback by regulating the currents flowing in the induction coils when the lever 2 pivots about two axes of articulation, for all the positions that can take said joystick in a given angular range.

In this embodiment (FIG. 4) there are thus third pole pieces 20 and fourth pole pieces 22. The third set and the fourth set each comprise a third pole piece 20 and a fourth pole piece 22 separated by a magnet 16 of which the north pole is attached to the third pole piece 20 and whose south pole is attached to the fourth pole piece 22.

When the mini-stick according to the invention is intended to be used in the field of aeronautics, severe safety standards apply and it is in particular expected to have a redundancy of electrical systems. It is easy in the case of the present invention to provide a redundant circuit. We may consider splitting all the magnetic circuits. However, given the intrinsic safety of the pole pieces themselves, only redundancy at the induction coils is necessary. FIG. 5 illustrates a mini-stick for which the coils 18 have been doubled so as to have a redundant system.

FIG. 6 illustrates a simplified variant embodiment of the present invention with respect to the embodiment of FIG. 4.

For the description of the embodiments of Figures 6 to 8, the references used in Figures 1 to 5 are repeated to designate similar elements even if they are of different shape.

In the variant of Figure 6, there is a hinge part called thereafter ball 4 attached to a lever 2. The ball 4 comprises a central magnet 6 having the shape of a half-disk and disposed between a first part 8 quarter-shaped sphere and a second portion 10 also quarter-sphere shape. Compared to the previous embodiments, the orientation of the handle 2 relative to the magnet 6 is different. While in the previous embodiments, the handle 2 was perpendicular to the magnet 6, it is in the plane of the magnet 6 in Figure 6. In addition, to create a counter-force on the ball 4, a mechanical ball 5 (and its corresponding bearing not shown) for example is also expected.

Whereas in the embodiment of FIG. 4 there were altogether eight pole pieces, the embodiment of FIG. 6 provides four pole pieces, a first pole piece 12 facing (only) at first part 8, a second piece polar part 14 facing (only) with first part 10, a third pole piece 20 facing (only) with first part 8 and a fourth pole piece 22 facing (only) with first part 10. With each pole piece is associated a induction coil 18 to allow the magnetic field to be modified in the gap between each pole piece and the ball 4. The first pole piece 12 and the second pole piece 14 can act on the ball 4 by circulating a current in the coils 18 induction, so as to exert a resistant torque on the ball 4 or to move the lever 2 without action from a user (in a vion for example, when a mini-round is doubled, it is known to move the second mini-stick in the position that a user has taken the first mini-round). Similarly, in another plane, perpendicular to the plane of action of the first pole piece 12 and the second pole piece 14, the third pole piece 20 and the fourth pole piece 22 can act, by circulating a suitable current in the corresponding induction coils 18, on the ball 4.

The polar parts are here also biased by a magnet 16 (and by the coils 18). Sets are also formed with a magnet 16 sandwiched between two pole pieces. However, whereas in the embodiment of FIG. 4 such an assembly concerned two pole pieces acting in the same plane, here a pole piece of the set relates to an action in one plane and the other relates to an action in the plane. perpendicular. One thus forms an assembly with a magnet 16, the first pole piece 12 and the fourth pole piece 22 and another set around another magnet 16 with the second pole piece 14 and the third pole piece 20 (and of course, at each pole piece, in each of the sets, is also at least one induction coil 18). The skilled person will immediately notice that in this case it is no longer a question of interconnecting the coils 18 of the same set.

The embodiment illustrated in FIG. 7 completely decouples the action exerted by the system on the lever 2 according to a first axis of articulation of the lever 2 of the action exerted on it according to a second axis of articulation. In addition, the handle 2 is not fixed relative to a ball but a transmission mechanism is provided between the handle 2 and the elements mounted as magnetic bearings.

First, in this embodiment, the handle 2 is articulated through a system obtained by combining a gimbal 24 and a pantograph 26 so that when the lever 2 pivots in a direction x, it causes in rotation an X axis and when the lever 2 pivots in a direction y, it rotates a Y axis. In the embodiment illustrated in Figure 7, the X axis carries at one of its ends the cardan 24 while the pantograph 26 rotates the Y axis.

The X axis and the Y axis each carry a part comprising a first part 8 made of magnetic material polarized according to a first magnetic polarity and a second portion 10 of magnetic material polarized according to a reverse magnetic polarity with respect to the first magnetic polarity. This piece is called here too, as in this document, "patella". To distinguish the two ball joints, the ball carried by the X axis is referenced 4X while the other ball, carried by the Y axis is referenced 4Y. Each ball is integral with the axis that carries it. Figure 7 proposes to conform each ball in a circular cylinder portion having in the middle position a magnet 6 on either side of which is a first portion 8 of magnetic material and a second portion 10 of magnetic material. Those skilled in the art will understand that this is a form chosen from many others. To avoid having a significant imbalance on the X axis and the Y axis, one could thus have a 4X ball joint and a 4Y ball joint better distributed around its pivot axis, the axis 4X or 4Y corresponding for example to a longitudinal axis passing through the center of gravity of the corresponding ball joint. A substantially spherical or hemispherical shape can also be envisaged here. The presence of unbalance is however mechanically interesting here because it allows to add an additional force (gravity) to act on the joystick 2 and create a return effort. The ball joints 4X and 4Y are indeed positioned on the X axis and the Y axis so that their stable equilibrium position corresponds to the "rest" position of the lever 2. It should be noted here that the system between the 4X and 4Y ball joints could be different from the system illustrated in FIG. 7. It is important, however, that, on the one hand, the lever 2 can rotate the X and Y axes and that, on the other hand, an action on the X and Y axes can be retransmitted to the controller. The transmission system between the ball joints and the handle must therefore be reversible.

The patella 4X is placed between two pole pieces: a first pole piece 12 facing the first part 8 (only) of the ball 4X and a second pole piece 14 facing (only) the second part 10 of the ball 4X. Similarly, the ball 4Y is placed between two pole pieces: a third pole piece 20 facing (only) the first part 8 of the ball 4Y and a fourth pole piece 22 facing (only) at the second part 10 of the 4Y ball joint. Each pole piece is associated, on the one hand, with a magnet 16 polarizing it and, on the other hand, an induction coil 18. The end of the pole pieces facing the corresponding ball is here also shaped so that the air gap is substantially constant over the entire surface vis-à-vis in the rest position, this gap varies when the corresponding ball pivots around its axis. The pole pieces are each facing a portion of the corresponding ball joint of the same magnetic polarity so as to create a repulsive force all the greater as the gap decreases. Here we arrive at a stable equilibrium when all air gaps are equal (for magnetic fields of equal amplitude).

A fifth embodiment is illustrated in Figures 8a and 8b. This is actually an alternative embodiment of the third embodiment of Figure 6. In this embodiment, the ball 4 is cubic (or parallelepiped). By means of suitable joints, a (lower) face of the cubic ball 4 remains parallel to a reference plane (for example horizontal). The ball 4 then moves between the four pole pieces of the system, the equilibrium position being reached when the four corresponding gaps are equal.

The described system is of course associated with electronic control and control means. Position sensors are provided to know the position of the lever 2. Depending on this position, and possibly other parameters internal or external to the mini-stick, a force feedback is determined by a computer, for example a microcontroller . Once this force return has been determined, the intensity of the effort (in Newton or in Newton meter) is converted into electrical intensity (in Ampere) to define the characteristics of the electric currents that will have to circulate in each induction coil so to obtain the desired return of effort.

These various elements (position sensors or motion sensors, possibly force sensor and / or displacement speed sensor of the joystick, computer, control system currents flowing in the coils, ...) are not represented on the drawing.

FIG. 9 shows a main control system 44 and A redundant control system 46. These two systems are similar and have the same structure. They can each be assembled to form an assembly, and the two sets obtained can be superimposed as illustrated in FIG. 9, on which only the elements of the main control system 44 are seen.

The main control system 44 includes a microcontroller 48 associated with a communication interface 50 with other electronic systems. If the lever 2 is intended for controlling the inclination of an aircraft (airplane or helicopter) along its roll axis and its pitch axis, provision is made for example a first set 52 for the regulation of the system on the axis roll and a second set 54, substantially similar to the first set 52, for regulating the system on the pitch axis.

Figure 9 also shows various elements of a mini-stick according to the invention to better illustrate the functions of the control system.

As can be seen from the foregoing description, the present invention makes it possible to produce a mini-stick that can be used for piloting an aircraft, airplane or helicopter, for example. This mini-stick may in particular serve as control member in rolling and pitching of the aircraft. A force feedback is integrated into the structure of the mini-stick. The efforts produced are due to the opposition of magnetic fields created between fixed pole pieces and a moving part in connection with a mini-handle lever. Air gaps are created between the fixed pole pieces and the moving part. An equilibrium, corresponding for example to a rest position, is obtained when all air gaps are identical.

The force feedback law is applied by managing flows of electric currents in induction coils. It is thus possible to have a fast and accurate control of the forces exerted on the handle of the mini-handle. The adjustment of the efforts (or couples) return can be obtained by calculation knowing the position of the joystick to manage and / or by adding force sensors to enslave the efforts (couples) returned.

The hinges described above can be maintained only by the magnetic bearings described (in particular Figure 4) but may also require mechanical guidance of the ball joint. Guidance of this type or of a another type, adapted to the situation (shape of the patella and environment), may be provided for the other embodiments.

The present invention is not limited to the embodiments described above by way of non-limiting examples and the variants mentioned. It also relates to all the variants within the scope of those skilled in the art within the scope of the claims below.

Claims

1. Mini-control sleeve with force feedback comprising a handle (2) having a degree of freedom in rotation about a first axis of articulation, characterized in that it comprises:

a part called the first articulation part (4) having a first part (8) having a first magnetic polarity and a second part (10) having a second magnetic polarity inverse to the first magnetic polarity,

reversible movement transmission means between the first articulation piece (4) and the handle (2) connecting the first articulation piece (4) to said handle (2) so that a rotational movement of the handle (2) around the first axis of articulation is transmitted to the first articulation part (4) which can also inversely drive the handle (2) in rotation about its first axis of articulation,

at least one pole piece, called the first pole piece (12), arranged facing substantially the first part (8) of the first articulation piece (4),

at least one other pole piece, called the second pole piece (14), arranged facing substantially the second portion (10) of the first articulation piece (4),

first polarization means (18) for acting on the first pole piece (12) to polarize it according to the first magnetic polarity,

second polarization means (18) making it possible to act on the second pole piece (14) to polarize it according to the second magnetic polarity,

means providing measurement signals representative of the position and / or movement of the handle (2) or of the articulation piece (4), and

control means acting on the first biasing means (18) and on the second biasing means (18) so as to vary the magnetic field created by the first biasing means (18) and the magnetic field created by the second polarization means (18) as a function of the position and / or motion measurement signals.

2. Mini-handle according to claim 1, characterized in that its lever (2) has a second degree of freedom around a second axis of articulation, and in that it further comprises:

a part called a second articulation part (4) having a third part (8) having a first magnetic polarity and a fourth part (10) having a second magnetic polarity inverse to the first magnetic polarity,

- reversible movement transmission means (24, 26) between the second articulation part (4) and the handle (2) connecting the second articulation part (4) to said handle (2) so that a rotational movement of the handle (2) about the second axis of articulation is transmitted to the second articulation part (4) which can also inversely cause the handle (2) to rotate about its second axis of articulation ,

at least one pole piece, called the third pole piece (20), arranged facing substantially the third portion (8) of the second articulation piece (4),

at least one other pole piece, called the fourth pole piece (22), arranged facing essentially the fourth portion (10) of the second articulation piece (4),

third polarization means (18) for acting on the third pole piece (20) to polarize it according to the first magnetic polarity, and

- Fourth polarization means (18) for acting on the fourth pole piece (22) to polarize it according to the second magnetic polarity.

3. Mini-control joystick with a handle (2) having a first degree of freedom in rotation about a first axis of articulation and a second degree of freedom in rotation about a second axis of rotation. articulation, characterized in that it comprises:

a part called hinge part (4) having a first part (8) having a first magnetic polarity and a second part (10) having a second magnetic polarity inverse of the first magnetic polarity,

- Reversible movement transmission means between the articulation piece (4) and the lever (2) connecting said articulation piece (4) to said handle (2) so that the movements of rotation of the joystick ( 2) about the first axis of articulation and about the second axis of articulation are transmitted to the articulation piece (4) which can also inversely drive the lever (2) in rotation about the first axis of articulation and around the second axis of articulation,

at least two pole pieces, said first pole piece (12) and third pole piece (20), arranged facing essentially the first part (8) of the articulation piece,

at least two other pole pieces, said second pole piece (14) and fourth pole piece (22), arranged facing substantially the second part (10) of the articulation piece,

first polarization means (18) for acting on the first and third pole pieces to polarize them according to the first magnetic polarity,

second polarization means (18) for acting on the second and fourth pole pieces to polarize them according to the second magnetic polarity,

control means acting on the first biasing means and on the second biasing means so as to vary the magnetic field created by the first polarization means and the magnetic field created by the second polarization means as a function of the polarization signals; measurement of position and / or movement.

4. Mini-handle according to one of claims 1 to 3, characterized in that a hinge part (4) comprises a central magnet (6) placed between two parts made of a magnetic material so that a part is polarized by the magnet (6) in a first magnetic polarity and that the other part is polarized by the magnet in a magnetic polarity inverse of the first magnetic polarity.

5. Mini-handle according to one of claims 1 to 4, characterized in that the polarization means comprise a coil (18) disposed around a core of magnetic material and means for supplying the coil with electrical current.

6. Mini-handle according to one of claims 1 to 5, characterized in that each pole piece is biased by a magnet (16).

7. Mini-handle according to one of claims 1 to 6, characterized in that each pole piece disposed vis-à-vis a hinge part portion has a surface facing the hinge piece made so that during a rotation of the hinge piece about an axis of articulation the distance between a given point of said surface and the hinge piece varies.